Floating fastener mounting structure and method

ABSTRACT

A floating fastener mounting structure and method is disclosed to include a metal panel member defining a convex wall portion and a mounting through hole at the convex wall portion, a mounting socket defining a center hole, an annular step around the outer perimeter and an annular locating groove around the outer perimeter and at the bottom side of the annular step and being riveted to the metal panel member to force the annular locating groove into engagement with the convex wall portion tightly, a spring member mounted in the mounting socket, and a lock screw floatably supported on the spring member in the mounting socket for detachably locking the metal panel member to an external metal panel member.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to floating fastener mounting technology and more particularly, to the fixation between a mounting socket of a floating fastener and a metal panel member using stamping technique, which provides high shear strength.

2. Description of the Related Art

When joining metal panel members, fastening devices respectively formed of a lock screw, a rotary knob and a washer may be used. During application, the lock screw, rotary knob and washer of each fastening device are assembled and then mounted at a first metal panel member. When fastening the first metal panel member to a second metal panel member, rotate the rotary knob of each fastening device to drive the respective lock screw into a respective mounting screw hole at the second metal panel member, and then use a hand tool to fasten tight the lock screw. This multiple metal panel member fastening method can be used in a machine tool or other situations where multiple metal panel members are to be fastened in a stack. In a machine tool, the location where metal panel members are fastened together may be at the power drive or speed-adjustment unit inside the housing. The lock screws of the fastening devices may fall from the metal panel members and missed easily due to user's negligence during a metal panel member dismounting procedure for the performance of a repair or speed adjustment operation, affecting further re-installation operation.

To avoid the aforesaid problem, floating fasteners are created. A floating fastener is known comprising a mounting socket A that comprises a bottom mounting portion A1 inserted into a mounting through hole B0 at a metal panel member B and welded thereto, a lock screw C1 inserted through a center hole A0 of the mounting socket A, a spring member C11 mounted around the shank of the lock screw C1 and stopped between an inside step A3 in the center hole A0 of the mounting socket A and the head of the lock screw C1 to floatably support the lock screw C1 in the mounting socket A, and a cap member C affixed to the head of the lock screw C1 and having an inside coupling flange C2 protruded from the inner perimeter thereof at a bottom side and slideably coupled to the outer perimeter of the mounting socket 1 between an external top annular flange A2 and an external bottom annular flange A11 of the mounting socket A. This design of floating fastener still has drawbacks as follows:

-   1. The bottom mounting portion A1 of the mounting socket A is     inserted into the mounting through hole B0 of metal panel member B     and attached to a solder paste B1 at the top wall of the metal panel     member B around the mounting through hole B0 and then welded thereto     through reflow soldering. Due to limited contact surface area     between the mounting socket A and the metal panel member B, the     structural strength between the mounting socket A and the metal     panel member B is not strong enough, and the bottom mounting portion     A1 of the mounting socket A may break easily when the mounting     socket A is stretched accidentally by an external force. -   2. When coupling the inside coupling flange C2 of the cap member C     to the outer perimeter of the mounting socket 1 between an external     top annular flange A2 and an external bottom annular flange A11 of     the mounting socket A, the applied force may stretch the mounting     socket A, loosening the mounting socket A or even forcing the     mounting socket A out of place.

Therefore, there is a strong demand for a floating fastener that eliminates the drawbacks of the aforesaid prior art design and that provides a high structural strength for repeated use.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide a floating fastener mounting structure and method, which facilitates quick installation and provides high structural strength and enhanced shear strength, avoiding accidental breaking.

To achieve this and other objects of the present invention, a floating fastener mounting structure comprises a metal panel member, a mounting socket affixed to the metal panel member, a lock screw mounted in the mounting socket, and a spring member mounted in the mounting socket to floatably support the lock screw in said mounting socket. The metal panel member comprises a mounting through hole, and a convex wall portion disposed around the mounting through hole and defining a bottom accommodation space. The mounting socket is upwardly inserted through the mounting through hole of the metal panel member, comprising a center hole vertically extending through opposing top and bottom sides thereof for accommodating the lock screw and the spring member, an annular step protruding from and extending around an outer perimeter near bottom side thereof, and an annular locating groove extending around the outer perimeter and abutted against a bottom side of the annular step and forced into engagement with the convex wall portion of the metal panel member. Further, the annular step defines a downwardly and outwardly sloping top surface for guiding the convex wall portion of the metal panel member downwardly over the annular step into engagement with the annular locating groove.

Further, the mounting socket comprises a transverse partition wall disposed in the center hole, and a through hole cut through opposing top and bottom sides of the transverse partition wall at the center. The lock screw comprises a head disposed outside the mounting socket, and a shank perpendicularly and downwardly extended from a bottom wall of the head at the center and terminating in a screw rod and inserted through the through hole on the transverse partition wall in the center hole of the mounting socket. The spring member is mounted around the shank of the lock screw in the center hole of the mounting socket and stopped between the head of the lock screw and the top side of the transverse partition wall of the mounting socket. Further, a C-shaped retainer is clamped on the shank of the lock screw and stopped between a bottom edge of the transverse partition wall of the mounting socket and the screw rod of the lock screw.

In an alternate form of the present invention, the aforesaid C-shaped retainer is eliminated, and the lock screw is fixedly mounted with a cap member that is axially slideably coupled to the mounting socket. The cap member is affixed to the head of the lock screw and axially slideably coupled to the outer perimeter of the mounting socket between an external top annular flange and the annular step of the mounting socket.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a mounting socket mounting structure of a floating fastener in accordance with the present invention.

FIG. 2 is a schematic drawing of the present invention, illustrating the mounting socket and the metal panel member temporarily secured together for riveting.

FIG. 3 corresponds to FIG. 2 illustrating the mounting socket and the metal panel member riveted together in the stamping press.

FIG. 4 is a flow chart of the mounting procedures of the mounting socket mounting structure in accordance with the present invention.

FIG. 5 is an exploded view of the floating fastener in accordance with the present invention.

FIG. 6 corresponds to FIG. 5 when viewed from another angle.

FIG. 7 is an elevational assembly view of the floating fastener in accordance with the present invention.

FIG. 8 is a sectional side view of the floating fastener in accordance with the present invention.

FIG. 9 is an exploded view of an alternate form of the floating fastener in accordance with the present invention.

FIG. 10 is a sectional assembly view of the alternate form of the floating fastener in accordance with the present invention.

FIG. 11 is an exploded view of a floating fastener according to the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1, 2 and 3, a mounting socket mounting structure of a floating fastener in accordance with the present invention is shown. The mounting socket mounting structure comprises a mounting socket 1, and a metal panel member 2.

The mounting socket 1 is an open-ended cylindrical member comprising a center hole 10 vertically extending through opposing top and bottom sides thereof, an annular step 11 protruding from and extending around the outer perimeter thereof near the bottom side and spaced above the bottom side at a predetermined distance, and an annular locating groove 12 extending around the outer perimeter and abutted against the bottom side of the annular step 11. The annular step 11 defines a downwardly and outwardly sloping top surface 111.

The metal panel member 2 comprises a mounting through hole 20, and a convex wall portion 21 disposed around the mounting through hole 20 and defining a bottom accommodation space 210. The mounting through hole 20 has a diameter equal to or slightly greater than the diameter of the outer perimeter of the mounting socket 1 and smaller than the diameter of the annular step 11 of the mounting socket 1.

Referring to FIG. 4 and FIGS. 1-3 again, the mounting socket 1 is installed in the mounting through hole 20 of the metal panel member 2 subject to the following steps:

-   (100) Insert the mounting socket 1 upwardly through the mounting     through hole 20 of the metal panel member 2. -   (101) Force the annular step 11 of the mounting socket 1 into     friction engagement with the convex wall portion 21 of the metal     panel member 2. -   (102) Place the temporarily attached mounting socket 1 and metal     panel member 2 on a worktable 3 of a stamping press in vertical     alignment with a negative mold cavity 310 of a stamping die 31, and     then operate the stamping press to stamp the negative mold cavity     310 of the stamping die 31 onto the mounting socket 1, causing the     bottom edge 311 of the stamping die 31 around the negative mold     cavity 310 to deform the convex wall portion 21 of the metal panel     member 2 and to force the convex wall portion 21 of the metal panel     member 2 over the downwardly and outwardly sloping top surface 111     of the annular step 11 of the mounting socket 1 into engagement with     the annular locating groove 12; -   (103) finishing installation of the metal panel member 2 in the     mounting socket 1.

When applying an upward force to the mounting socket 1 to insert the mounting socket 1 upwardly through the mounting through hole 20 of the metal panel member 2, the annular step 11 of the mounting socket 1 will be forced into friction engagement with the convex wall portion 21 of the metal panel member 2, and thus the mounting socket 1 and the metal panel member 2 are temporarily secured together. Thereafter, the temporarily attached mounting socket 1 and metal panel member 2 are placed on the worktable 3 of the prepared stamping press in vertical alignment with the negative mold cavity 310 of the stamping die 31. Thereafter, the stamping press is operated to stamp the negative mold cavity 310 of a stamping die 31 onto the mounting socket 1. At this time, the bottom edge 311 of the stamping die 31 around the negative mold cavity 310 gives a downward pressure to the convex wall portion 21 of the metal panel member 2, forcing the convex wall portion 21 of the metal panel member 2 over the downwardly and outwardly sloping top surface 111 of the annular step 11 of the mounting socket 1 into engagement with the annular locating groove 12, and thus the metal panel member 2 is riveted onto the mounting socket 1, providing high shear strength.

Referring to FIGS. 5-8 and FIGS. 1 and 3 again, the mounting socket 1 further comprises an external bottom annular flange 13 extending around the outer perimeter in flush with the bottom side thereof and abutted at the bottom side of the annular locating groove 12. When riveting the metal panel member 2 onto the mounting socket 1, the external bottom annular flange 13 of the mounting socket 1 will be forced into the bottom accommodation space 210 beneath the convex wall portion 21 of the metal panel member 2 and kept in flush with the bottom surface of the metal panel member 2, enhancing the shear strength. The mounting socket 1 further comprises a transverse partition wall 14 disposed in the center hole 10 at a selected elevation, and a through hole 140 cut through opposing top and bottom sides of the transverse partition wall 14 at the center in a concentric manner relative to the center hole 10. A lock screw 4 is inserted through the through hole 140 in the center hole 10 of the mounting socket 1. The lock screw 4 comprises a head 41, an operation portion 414 located on the top wall of the head 41, and a shank 411 perpendicularly and downwardly extended from the bottom wall of the head 41 at the center and terminating in a screw rod 412. A spring member 42 is mounted around the shank 411 of the lock screw 4 in the center hole 10 of the mounting socket 1 and stopped between the head 41 of the lock screw 4 and the top side of the transverse partition wall 14 of the mounting socket 1. Further, a C-shaped retainer 43 is clamped on the shank 411 of the lock screw 4 and stopped between the bottom edge 141 of the transverse partition wall 14 of the mounting socket 1 and the screw rod 412 of the lock screw 4. Thus, the lock screw 4 is floatably positioned in the center hole 10 of the mounting socket 1.

FIGS. 9 and 10 illustrate an alternate form of the present invention. This alternate form is substantially similar to that shown in FIGS. 1-8 with the exception that the mounting socket 1 in accordance with this alternate form further comprises an external top annular flange 15 extending around the periphery near the top side thereof. Further, the diameter of the external top annular flange 15 is smaller than the diameter of the annular step 11. The mounting socket 1 is assembled with a lock screw 4, a cap member 44 and a spring member 42, forming a floating fastener. The lock screw 4 is inserted through the through hole 140 in the center hole 10 of the mounting socket 1, comprising a head 41, a locating flange 413 extending around the periphery of the head 41, an operation portion 414 located on the top wall of the head 41, and a shank 411 perpendicularly and downwardly extended from the bottom wall of the head 41 at the center and terminating in a screw rod 412. The spring member 42 is mounted around the shank 411 of the lock screw 4 in the center hole 10 of the mounting socket 1 and stopped between the head 41 of the lock screw 4 and the top side of the transverse partition wall 14 of the mounting socket 1. The cap member 44 is affixed to the head 41 of the lock screw 4 and axially slideably coupled to the mounting socket 1. As illustrated, the cap member 44 comprises a top center hole 440 press-fitted onto the periphery of the head 41 of the lock screw 4 above the locating flange 413, a locating groove 441 extending around an inner perimeter thereof and forced into engagement with the locating flange 413 of the lock screw 4 tightly, and an inside coupling flange 442 protruded from the inner perimeter at a bottom side. Subject to the elastic material property of the cap member 44, the inside coupling flange 442 of the lock screw 4 can be forced downwardly over the external top annular flange 15 of the mounting socket 1 and slideably coupled to the periphery of the mounting socket 1 between the external top annular flange 15 and the annular step 11.

Further, the operation portion 414 of the lock screw 4 can be a tool slot, for example, straight slot, crossed slot, star shaped slot or hexagonal slot. Alternatively, the operation portion 414 can be a block, for example, straight block, crossed block, star shaped block or hexagonal block protruded from the top wall of the head 41 of the lock screw 4. A mating screwdriver, wrench or hand tool can be attached to the operation portion 414 and operated to turn the lock screw 4.

In conclusion, the invention provides a mounting socket 1 that is an open-ended cylindrical member comprising a center hole 10 vertically extending through opposing top and bottom sides thereof, an annular step 11 protruding from and extending around the outer perimeter thereof near the bottom side and spaced above the bottom side at a predetermined distance and defining a downwardly and outwardly sloping top surface 111, and an annular locating groove 12 extending around the outer perimeter and abutted against the bottom side of the annular step 11, and an external bottom annular flange 13 extending around the periphery in flush with the bottom side thereof and abutted at the bottom side of the annular locating groove 12. The mounting socket 1 can be conveniently and tightly riveted to a mounting through hole 20 in a convex wall portion 21 of a metal panel member 2 to provide high shear strength, and assembled with a lock screw 4 and a spring member 42 and a C-shaped retainer 43 or cap member 44 to form a floating fastener.

In actual application, the invention has the following advantages and features:

-   1. Subject to the matching design between the annular step 11 and     annular locating groove 12 of the mounting socket 1 and the mounting     through hole 20 and convex wall portion 21 of the metal panel member     2, the mounting socket 1 and the metal panel member 2 can be tightly     riveted together, providing high shear strength. -   2. After the mounting socket 1 and the metal panel member 2 are     tightly riveted together, the mounting socket 1 can be assembled     with a lock screw 4 and a spring member 42 and a C-shaped retainer     43 or cap member 44 to form a floating fastener for detachably and     positively locking the metal panel member 2 to another metal panel     member.

Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. 

What the invention claimed is:
 1. A floating fastener mounting structure, comprising a metal panel member, a mounting socket affixed to said metal panel member, a lock screw mounted in said mounting socket, and a spring member mounted in said mounting socket to floatably support said lock screw in said mounting socket, wherein: said metal panel member comprises a mounting through hole, and a convex wall portion disposed around said mounting through hole and defining a bottom accommodation space; said mounting socket is upwardly inserted through said mounting through hole of said metal panel member, comprising a center hole vertically extending through opposing top and bottom sides thereof for accommodating said lock screw and said spring member, an annular step protruding from and extending around an outer perimeter near bottom side thereof, and an annular locating groove extending around the outer perimeter and abutted against a bottom side of said annular step and forced into engagement with said convex wall portion of said metal panel member, said annular step defining a downwardly and outwardly sloping top surface for guiding said convex wall portion of said metal panel member downwardly over said annular step into engagement with said annular locating groove.
 2. The floating fastener mounting structure as claimed in claim 1, wherein said mounting socket further comprises a transverse partition wall disposed in said center hole, and a through hole cut through opposing top and bottom sides of said transverse partition wall at the center; said lock screw comprises a head disposed outside said mounting socket, and a shank perpendicularly and downwardly extended from a bottom wall of said head at the center and terminating in a screw rod and inserted through the through hole on said transverse partition wall in said center hole of said mounting socket; said spring member is mounted around said shank of said lock screw in said center hole of said mounting socket and stopped between said head of said lock screw and the top side of said transverse partition wall of said mounting socket.
 3. The floating fastener mounting structure as claimed in claim 2, further comprising a C-shaped retainer clamped on said shank of said lock screw and stopped between a bottom edge of said transverse partition wall of said mounting socket and said screw rod of said lock screw.
 4. The floating fastener mounting structure as claimed in claim 1, wherein said mounting socket further comprises a transverse partition wall disposed in said center hole, a through hole cut through opposing top and bottom sides of said transverse partition wall at the center, and an external top annular flange extending around the outer perimeter near the top side thereof; said lock screw comprises a head disposed outside said mounting socket, a shank perpendicularly and downwardly extended from a bottom wall of said head at the center and terminating in a screw rod and inserted through the through hole on said transverse partition wall in said center hole of said mounting socket, and a cap member affixed to said head and axially slideably coupled to the outer perimeter of said mounting socket between said external top annular flange and said annular step of said mounting socket; said spring member is mounted around said shank of said lock screw in said center hole of said mounting socket and stopped between said head of said lock screw and the top side of said transverse partition wall of said mounting socket.
 5. The floating fastener mounting structure as claimed in claim 4, wherein said external top annular flange has a diameter smaller than the diameter of said annular step.
 6. The floating fastener mounting structure as claimed in claim 4, wherein said mounting socket further comprises an external bottom annular flange extending around the outer perimeter in flush with the bottom side thereof and abutted at a bottom side of said annular locating groove and accommodated in said bottom accommodation space of said metal panel member.
 7. The floating fastener mounting structure as claimed in claim 4, wherein said lock screw further comprises an operation portion located on a top wall of said head in one of the forms of straight slot, crossed slot, star shaped slot, hexagonal slot, straight block, crossed block, star shaped block and hexagonal block, for the positioning of a hand tool operable to rotate said lock screw.
 8. The floating fastener mounting structure as claimed in claim 4, wherein said lock screw further comprises a locating flange extending around the periphery of said head; said cap member comprises a top center hole press-fitted onto the periphery of said head and stopped above said locating flange, and a locating groove extending around an inner perimeter thereof and forced into engagement with said locating flange of said lock screw.
 9. A floating fastener mounting method, comprising the steps of: (a) inserting a mounting socket upwardly into a mounting through hole in a convex wall portion of a metal panel member to have an annular step at an outer perimeter of said mounting socket be stopped at a bottom side of said convex wall portion; (b) forcing said annular step of said mounting socket into friction engagement with said convex wall portion of said metal panel member; (c) riveting said mounting socket and said metal panel member to force said convex wall portion of said metal panel member over said annular step of said mounting socket into engagement with said annular locating groove of said mounting socket; and (d) finishing installation of said metal panel member in said mounting socket.
 10. The floating fastener mounting method as claimed in claim 9, wherein said mounting socket prepared in step (a) is processed to provide a center hole vertically extending through opposing top and bottom sides thereof and an annular locating groove extending around the outer perimeter thereof and abutted against a bottom side of said annular step.
 11. The floating fastener mounting method as claimed in claim 9, wherein said convex wall portion of said metal panel member prepared in step (a) is processed using stamping technique to provide said mounting through hole, and a bottom accommodation space surrounded by said convex wall.
 12. The floating fastener mounting method as claimed in claim 9, wherein said mounting socket prepared in step (a) is processed to provide an external bottom annular flange extending around the outer perimeter in flush with the bottom side thereof and abutted at a bottom side of said annular locating groove, and said annular step of said mounting socket is processed to provide a downwardly and outwardly sloping top surface.
 13. The floating fastener mounting method as claimed in claim 9, wherein step (c) of riveting said mounting socket and said metal panel member comprising the sub step of placing the temporarily attached said mounting socket and said metal panel member on a worktable of a stamping press in vertical alignment with a negative mold cavity of a stamping die, and the sub step of operating said stamping press to stamp said negative mold cavity of said stamping die onto said mounting socket, striking a bottom edge of said stamping die around said negative mold cavity against said convex wall portion of said metal panel member and forcing said convex wall portion of said metal panel member over said annular step of said mounting socket into engagement with said annular locating groove.
 14. The floating fastener mounting method as claimed in claim 9, further comprising step (d): mounting a spring member and a lock screw in said mounting socket in a floating manner by inserting said lock screw through a through hole at the center of a transverse partition wall in a vertical center hole of said mounting socket and setting said spring member in said mounting socket around a shank of said lock screw between a head of lock screw and said transverse partition wall of said mounting socket, and then fastening to said shank of said lock screw a C-shaped retainer stoppable below said transverse partition wall.
 15. The floating fastener mounting method as claimed in claim 9, further comprising step (d): mounting a spring member and a lock screw in said mounting socket in a floating manner by inserting said lock screw through a through hole at the center of a transverse partition wall in a vertical center hole of said mounting socket and setting said spring member in said mounting socket around a shank of said lock screw between a head of lock screw and said transverse partition wall of said mounting socket, and then coupling a cap member at said head of said lock screw to the outer perimeter of said mounting socket for allowing said cap member to be moved up and down with said lock screw relative to said mounting socket between said annular step and a top annular flange at a top side of the outer perimeter of said mounting socket. 